Introduction
Introduction
GPS (Global Positioning System), also known as NAVSTAR (NAVigation Satellite Time And Ranging) had its first satellite launched in 1978.
Below are the 4 constellations of GNSS systems:
- Global Positioning System (GPS) - United States
- Standard Positioning Service (SPS)
- Precise Positioning Service (PPS)
- GLONASS - Russia
- Galileo - Europe
- Open service (OS)
- Public regulated service (PRS)
- Beidou(/Compass) - China
Their properties are:
